There are several but my favourites are morning thunder, and pass wind!
Audible expulsion of surplus gaseous, usually occurring in over-crowded rooms.
Flatulant
Had gas or passed gas but if you are not that posh and you just want another word one is fluff.
It's a posh way of saying fart
a posh word for the word big is Gargantuan.
Highfalutin
yes, its a very posh word and nobody but posh people say it anymore.
The posh word for blurb is "synopsis" or "teaser."
the word doff is not another word for posh. doff means to remove or take off, as clothing.
A Posh Font on MS Word is "French Script MT".
Lemonard
recreation
posh word for when the pollen from one flower reaches another
Fart is not a nice word. There you go, there's a sentence using the word.